About every semester I make the same mistake, and I usually waste 30 minutes to an hour to try and figure it out. When I do, I feel like an idiot. So I’m writing this in hopes that I’ll remember next time.<\/p>\n
Every semester I’ll have a program to turn in, and I’ll have to compile it on the school UNIX server to turn in. When we get our preference of language, I usually choose C++. I open up Visual Studio and write my program, debug it and get it all working. I try to keep everything very general and remove all Microsoft-specific code. Then I FTP it to the UNIX server and try to compile:<\/p>\n
\n# gcc prog1hw.c\r\nUndefined\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 first referenced\r\n symbol\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 in file\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string[in-charge](std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator=(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::append(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string[in-charge]()\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string [in-charge]()\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator+=(char)\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_ios<char, std::char_traits<char> >::eof() const\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string[in-charge](char const*, std::allocator<char> const&)\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_fstream<char, std::char_traits<char> >::open(char const*, std::_Ios_Openmode)\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_fstream<char, std::char_traits<char> >::~basic_fstream [in-charge]()\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_fstream<char, std::char_traits<char> >::basic_fstream[in-charge]()\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_istream<char, std::char_traints<char> >::ignore(int, int)\/var\/tmp\/\/ccNHY1WB.o\r\n std::allocator<char>::~allocator [in-charge]()\/var\/tmp\/\/ccNHY1WB.o\r\n std::allocator<char>::allocator[in-charge]()\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::length() const\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::at(unsigned)\/var\/tmp\/\/ccNHY1WB.o\r\n std::cout\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_ios<char, std::char_traits<char> >::clear(std::_Ios_Iostate)\/var\/tmp\/\/ccNHY1WB.o\r\n std::ios_base::Init::~Init [in-charge]()\/var\/tmp\/\/ccNHY1WB.o\r\n std::ios_base::Init::Init[in-charge]()\/var\/tmp\/\/ccNHY1WB.o\r\n __gxx_personality_v0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_istream<char, std::char_traints<char> >::get()\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_fstream<char, std::char_traits<char> >::close()\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_istream<char, std::char_traits<char> >& std::getline<char, std::char_traits<char>, std::allocator<char> >(std::basic_istream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> >&)\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_fstream<char, std::char_traits<char> >::is_open()\/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_string<char, std::char_traits<char>, std::allocator<char> >::insert(unsigned, char const*)\/var\/tmp\/\/ccNHY1WB.o\r\n std::cin\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \/var\/tmp\/\/ccNHY1WB.o\r\n std::basic_ostream<char, std::char_traits<char> >& std::operator<< <char, std::char_traits<char>, std::allocator<char> >(std::basic_ostream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)\/var\/tmp\/\/ccNHY1WB.o\r\n ld: fatal: Symbol referencing errors. No output written to a.out\r\n collect2: ld returned 1 exit status<\/pre>\n<\/blockquote>\nWhat strange stuff is this? It looks like something isn’t being included correctly. Okay…so I go back and start changing stuff. Do I need to add .h on my includes? No, same error. Do I need a newline at the end of the file? No. Maybe I didn’t FTP it correctly…maybe I used binary mode instead of ASCII mode. Nope. Is there something with the compiler? Maybe I need to try a certain switch…after 20 minutes of reading man pages…nope. It’s not finding the string class…have they removed the string class for some reason? What’s going on here?!? And I spend about 30 minutes to an hour trying to figure it out until I realize…<\/p>\n
I’m using gcc instead of g++. I’m using a C compiler for a C++ program. Do’h! And I KNOW why I do this, it’s because when I first had any real interaction in a UNIX environment at Cameron University, they set up a symbolic link so gcc was really calling g++. So whenever I want to compile a C++ program in a UNIX environment, I always go for gcc first. ARGH.<\/p>\n","protected":false},"excerpt":{"rendered":"
About every semester I make the same mistake, and I usually waste 30 minutes to an hour to try and figure it out. When I do, I feel like an idiot. So I’m writing this in hopes that I’ll remember next time. Every semester I’ll have a program to turn in, and I’ll have to […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[24,4,114],"tags":[223,222,225,82,17,224],"_links":{"self":[{"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/108"}],"collection":[{"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=108"}],"version-history":[{"count":3,"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/108\/revisions"}],"predecessor-version":[{"id":111,"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/108\/revisions\/111"}],"wp:attachment":[{"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=108"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=108"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/brianschettler.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=108"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}